Add a solution for Euler #288.

It's very slow , but is working fine.

categories/euler/prob288-shlomif.p6

@@ -0,0 +1,47 @@
+use v6;
+
+sub factorial_factor_exp($n , $f)
+{
+    if ($n < $f)
+    {
+        return 0;
+    }
+    else
+    {
+        my $div = $n / $f;
+        return $div + factorial_factor_exp($div, $f);
+    }
+}
+
+my @t_n;
+
+my $N_LIM = 10;
+my $BASE = 61;
+my $LIM = 10_000_000;
+
+my $S_0 = 290797;
+my $s = $S_0;
+
+for (0 .. $N_LIM-1) -> $n {
+    @t_n.push($s % $BASE);
+    $s = (($s * $s) % 50515093);
+}
+
+my $sum = 0;
+for ($N_LIM .. $LIM) -> $n {
+    if $n % 10_000 == 0 {
+        say "Reached $n";
+    }
+    $sum += ($s % $BASE);
+    $s = (($s * $s) % 50515093);
+}
+
+sub f($n)
+{
+    return factorial_factor_exp($n, ($BASE)) % (($BASE) ** $N_LIM);
+}
+
+say "Solution == ", +([+] (
+    (map { f(($BASE) ** $_) * @t_n[$_] }, 1 .. @t_n-1),
+    $sum * f(($BASE) ** $N_LIM)
+)) % (($BASE) ** $N_LIM);